A Long-Term Evolution (LTE) system offers high peak data rates, low latency, improved system capacity, and low operating cost resulting from simple network architecture. An LTE system also provides seamless integration to older wireless network, such as GSM, CDMA and Universal Mobile Telecommunication System (UMTS). In LTE systems, an evolved universal terrestrial radio access network (E-UTRAN) includes a plurality of evolved Node-Bs (eNodeBs or eNBs) communicating with a plurality of mobile stations, referred as user equipments (UEs). Enhancements to LTE systems are considered so that they can meet or exceed International Mobile Telecommunications Advanced (IMT-Advanced) fourth generation (4G) standard. In LTE networks, Physical Broadcast Channel (PBCH) is used for broadcasting information to different UEs.
The signal bandwidth for next generation 5G new radio (NR) systems is estimated to increase to up to hundreds of MHz for below 6 GHz bands and even to values of GHz in case of millimeter wave bands. Furthermore, the NR peak rate requirement can be up to 20 Gbps, which is more than ten times of LTE. Three main applications in 5G NR system include enhanced Mobile Broadband (eMBB), Ultra-Reliable Low Latency Communications (URLLC), and massive Machine-Type Communication (MTC) under milli-meter wave technology, small cell access, and unlicensed spectrum transmission. Multiplexing of eMBB & URLLC within a carrier is also supported.
Polar coding is adopted for NR-PBCH transmission. NR-PBCH carries the master control information (e.g., similar to MIB in LTE), which includes system bandwidth, Hybrid Automatic Repeat Request (HARQ) info, system frame number (SFN), timing information, etc. with CRC attachment. Specifically, NR-PBCH uses 512-bit Polar code to carry total 56 data bits. However, different Polar code bit channels have different channel reliability. An NR-PBCH bit mapping design is sought to enhance NR-PBCH decoding performance.